How Do Sharks Sleep?

Posted by Erika Lang on

When it comes to the animal kingdom, every species has its own special way they prioritize sleep. Animals must worry about the weather, are they going to be warm enough at night? Or on the flip side, how do they keep from overheating when it’s hot out? Are they going to be safe from predators while they sleep? Do they need a nest or will they be happy to sleep on a nice patch of grass? Do they sleep at night or do they sleep during the day? When we look at the animal kingdom we see that every species has its own preferences and particular ways they like to settle in for sleep. 

Much like us. Humans all have their own sleep patterns and the way we optimize our routine from sleep differs from person to person. What works for one person, might not work for the other. There is no one-size-fits-all when it comes to sleep, so we must find what works best for us. At Bear, we try and help you figure out what mattress works best for you with our Sleep Quiz

Let’s take a deeper look into the interesting sleep habits of various animals throughout the world. What can we learn from the ways animals sleep?

We’ll start with bears! (We’re biased what can we say.) 

A bear asleep.


Bears are omnivores and are found in various parts of the world including North America, Europe, and Asia. The sleep habits of bears vary greatly depending on the species and their environment.

Some species of bears, such as the brown bear, black bear, and polar bear, hibernate for several months during the winter months. During hibernation, the bear's metabolism slows down significantly and they enter a deep sleep. While hibernating, a bear's heart rate can drop from 40 beats per minute to just 8 beats per minute, and their body temperature drops from 37°C to just above freezing. This allows the bear to conserve energy and survive the long, harsh winter months when food is scarce. Grizzly bears for example can be taking in over 20,000 calories a DAY in the summer to prepare for hibernation. Which equates to about 3 pounds. They use the fat they build up during the warmer months to keep their bodies ticking throughout hibernation. 

Bears understand the importance of getting the temperature just right when it’s time to fall asleep. In Yellowstone National Park, when bears are building their dens for hibernation they ensure to keep the entrance just large enough for the bear themself to fit through and then use the snow to insulate the entrance. The chamber itself is dug only slightly bigger than the bear so it can maximize the heat retention within its den. Temperature affects the way we sleep dramatically. If you tend to sleep on the hot side, the GlacioTex Mattress Protector could be a great option as it comes built with cooling technology as do all of the mattresses we sell at Bear. 

However, not all species of bears hibernate. For example, the sun bear and the spectacled bear do not hibernate. Instead, they may take short naps during the day and night, sleeping for several hours at a time. They may also sleep for longer periods when food is abundant, and they have a full belly. When sleeping, bears may curl up in a ball or stretch out on their stomachs, depending on their level of comfort and the environment. Like humans have their own personal favorite sleep positions, so do bears! Some of us go for the curled up into a little ball position while some of us prefer being sprawled out on our stomachs. 

A shark swimming


Sharks belong to the class Chondrichthyes and are found in oceans all over the world. Unlike bears and other mammals, sharks do not sleep in the traditional sense. Most species of sharks must keep swimming continuously in order to breathe and pump water over their gills. This constant movement is necessary to supply the shark's body with oxygen.

However, some species of sharks, such as the whale shark, have been observed resting motionless on the ocean floor. It is not clear if they are truly sleeping during these periods, as the whale shark is capable of obtaining oxygen through its skin and mouth while at rest.

In addition, some species of sharks, such as the nurse shark, are capable of slowing down their metabolism and resting on the ocean floor for short periods of time. During these periods, the nurse shark's heart rate may drop from 80 beats per minute to just 10 beats per minute. Similar to bears during hibernation, albeit for a shorter amount of time. However, the nurse shark must still move its gills in order to extract oxygen from the water.

A tiny bug on a finger


Insects are found in nearly every environment on Earth. The sleep habits of insects vary greatly depending on the species and their environment.

Some insects, such as bees and ants, do not sleep. Instead, they work continuously, gathering food, caring for their young, and maintaining their colonies. 

Other insects, such as butterflies and moths, do sleep, but their sleep patterns are different from those of mammals. Insects typically enter a state of torpor, a type of sleep characterized by a reduced level of activity and a decrease in metabolism. During torpor, the insect's heart rate slows, and it may become less responsive to stimuli.

For example, caterpillars are known to enter a state of torpor during the day when it is hot, and they are unable to find food. During this time, the caterpillar's heart rate slows, and it becomes less responsive to stimuli. When night falls and the temperature cools, the caterpillar awakes, and its metabolism and heart rate return to normal.

Like humans, the sleep habits of bears, sharks, and insects vary greatly depending on the species and their environment. While bears may hibernate or take short naps, sharks must keep swimming to breathe, and some insects do not sleep at all. Regardless, each of these animals has evolved to survive in their respective environments by finding a method of obtaining the rest and relaxation they need to survive and thrive.

The diversity of sleep patterns and habits among these animals highlights the importance of understanding the unique adaptations and behaviors of different species. Further research into the sleep patterns of these animals can provide valuable insights into their behavior, biology, and ecology and in turn we can see how these insights can benefit humans in our own approaches to sleep.

It is also important to consider the impact that human activities, such as deforestation and climate change, may have on the sleep habits of these animals. For example, the loss of habitats may disrupt the hibernation patterns of bears, leading to decreased survival rates. Similarly, the increasing levels of noise and pollution in the oceans may prevent sharks from sleeping or resting properly.

In order to protect these species and their habitats, it is crucial to continue to study and understand the sleep habits of bears, sharks, and insects, as well as other animals. By doing so, we can gain a better understanding of the complex interplay between sleep and survival, and work to conserve these important species for future generations. The more we understand about the connection between animals and sleep, the more we can inform ourselves about how to best optimize our own bedtime habits.

animals bears insects sharks sleep sleep patterns

Next Previous

Product Pricing Details

We strive to bring you the lowest prices. The strike-through or reference price indicates the Product’s suggested retail price (SRP) and may not have been offered by us or other retailers at that price in the past and may not be offered for sale at that price on any future date. Thus, the strike-through price may not necessarily be the prevailing market price, regular retail price, or former price of a Product. In addition, Products may be offered by us or other retailers at the same or lower prices during future promotional events beginning on or after the last day of any advertised promotion. See Details